Current Time in IANA HST Timezone

Overview and Usage

HST is the standard time for the state of Hawaii (USA), which includes the main Hawaiian Islands (Oahu, Maui, Kauai, Big Island, Molokai, Lanai, Niihau, Kahoolawe). The zone is also used by the French Polynesian islands of Tahiti and the Cook Islands (Rarotonga). In the IANA time zone database, HST is represented by zones such as Pacific/Honolulu, Pacific/Tahiti, Pacific/Rarotonga, America/Adak (for the Aleutian Islands, which observe HST in winter but switch to daylight time), and US/Hawaii. However, the core HST region (Hawaii) does not change clocks.

Offset and Abbreviation

HST is 10 hours behind Coordinated Universal Time (UTC-10). The abbreviation HST stands for Hawaii Standard Time. It is sometimes called Hawaii-Aleutian Standard Time (HAST) when referring to the zone that includes the Aleutian Islands, but in Hawaii, it is simply HST. The offset is constant: UTC-10:00 all year.

Daylight Saving Time: None

Hawaii has not observed daylight saving time since 1945, except for a brief period during World War II. The state is exempt from the US Uniform Time Act. Because Hawaii is near the equator, daylight hours vary little across the year (sunrise varies by about an hour, sunset by about an hour). This makes DST unnecessary. As a result, HST never shifts forward or backward, providing a stable time reference for residents and businesses.

Main Countries and Cities

• United States (Hawaii): Honolulu (capital), Hilo, Kailua-Kona, Kahului, Lihue.
• French Polynesia: Papeete (Tahiti).
• Cook Islands (New Zealand): Avarua (Rarotonga).
• United States (Alaska – Aleutian Islands): Adak (uses HST in winter, but switches to HDT in summer).

Business Hours and Scheduling

HST is 5 hours behind US Eastern Standard Time (EST) during standard time (when EST is UTC-5). When the US mainland is on daylight saving time (mid-March to early November), HST is 6 hours behind Eastern Daylight Time (EDT). For example, noon HST is 6:00 PM EDT. For the West Coast, HST is 2 hours behind Pacific Standard Time (PST) and 3 hours behind Pacific Daylight Time (PDT). When scheduling calls with Asia, note that HST is 19 hours behind Japan Standard Time (JST) and 18 hours behind China Standard Time (CST). For Australia (AEST), HST is 20 hours behind. For Europe, HST is 10 hours behind London (GMT/UTC) during winter and 11 hours behind British Summer Time (BST) in summer. A good rule: HST is among the last time zones to start the day; when it is 9 AM Monday in Honolulu, it is already 5 AM Tuesday in Sydney.

Practical Guidance

Because HST does not observe DST, you can rely on a constant offset when planning recurring meetings. However, be careful when the other party's zone shifts for DST: the time difference changes. For example, during US summer, HST is 6 hours behind New York (EDT); during US winter, it is 5 hours behind New York (EST). Always check the current DST status of the other zone. Use tools like world clocks that automatically adjust. For business hours overlap, typical working hours in HST (8 AM to 5 PM) overlap with US West Coast (10 AM to 5 PM PST/PDT) and US East Coast (1 PM to 5 PM EST/EDT). For Europe, only late afternoon HST overlaps with early morning European time (e.g., 3 PM HST = 1 AM next day in London). For Asia, there is no overlap during standard business hours; you may need to schedule early morning or late evening calls.